Generator condensate lift in absorption refrigeration apparatus



May 31, 1955 H. c. SHAGALOFF 2,709,345

GENERATOR CONDENSATE LIFT IN ABSORPTION REFRIGERATION APPARATUS 2 Sheets-Sheet 1 Filed Nov. 2, 1951 INVENTOR 6, 4 1 'I/ a) I 1 1a ATTOF/VAU May 31, 1955 Filed Nov. 2, 1951 SHAGALOFF ATE LIFT IN ABSORPTION REFRIGERATION APPARATUS H. C. GENERATOR CONDENS 2 Sheets-Sheet 2 INVENTOR. M6:

warfa km/a GENERATOR CGNDENSATE LIFT IN ABSORP- TION REFRIGERATION APPARATUS Harry C. Shagalolf, Evansville, Ind., assignor to Servel, Inc, New York, N. Y., a corporation of Delaware Application November 2, 1951, Serial No. 254,530

13 Claims. (Cl. 62-119) The present invention relates to refrigeration and more nited States Patent l particularly to auxiliary apparatus for heat operated refrigerated systems.

While the present invention may have other applications, it is particularly adapted for use in self-contained air conditioning units having a heat operated refrigeration system and a boiler for supplyingsteam thereto mounted on a common frame. Such air conditioning units have been used extensively for air conditioning residences, restaurants, stores and the like. The refrigeration system has a heat receiving element with a heating chamber to which steam is supplied from the boiler and a heat rejecting element with a heat exchanger through which cooling water flows. To provide a compact arrangement of the parts with a minimum overall height to adapt the units to be transported through door openings of usual dimensions, the bottom of the heating chamber is located below the liquid level in the boiler so that condensate must be lifted to return it to the boiler. It is also desirable in such air conditioning units to treat the cooling water with flue gas to reduce the scale on the heat transfer surfaces of the heat exchanger caused by the deposition of mineral carbonates.

One of the objects of the present invention is to provide an apparatus utilizing the flow of cooling water to provide a force for lifting condensate from the heating chamber to a level for gravity flow to the boiler.

Another object is to provide an apparatus utilizing the flow of cooling water to simultaneously draw flue gas into the water and return condensate from the heating chamber to the boiler.

Another object is to provide an apparatus utilizing the flow of cooling water to produce a suction for drawing flue gas into the water and utilizing the flow of flue gas to lift condensate from the heating chamber to a level above the boiler.

Still another object is to provide an apparatus for alternately producing a suction to lift condensate from the heating chamber to a level above the boiler and releasing the suction to permit the raised condensate to flow into the boiler by gravity.

These and other objects will become more apparent from the following description and drawings in which like reference characters denote like parts throughout the several views. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and not a definition of the limits of the invention, reference being had for this purpose to the appended claims. In the drawings:

Fig. l is a diagrammatic view of an air conditioning unit and showing the apparatus utilizing the flow of cooling Water to draw in line gas and return condensate to the boiler.

Fig. 2 is an enlarged sectional view of the venturi tube in the cooling water circuit.

Fig. 3 is an enlarged sectional view of the check valve in the flue gas circuit, and

Fig. 4 is a preferred arrangement for electrically actuating the control valves of the apparatus by a clock operated switch.

Referring to Fig. 1 of the drawings, the present invention is shown applied to an air conditioner for either cooling the air in the summer or heating air in the winter. The air conditioner comprises a source of heat illustrated in the form of a steam boiler 6, a heat operated refrigeration system 7, a heating system 8, a selective valve 9 for directing steam from the boiler to the heating system or refrigeration system, respectively, and a cooling tower 10. v

Boiler 6 may be of any suitable type such as the sectional cast-iron boiler illustrated and may be heated by any suitable fuel burner such as the gas burners 11. The sections of the boiler 6 are enclosed in a casing or hood 12 having an outlet pipe 13 and the hood and outlet pipe form a flue 14 for the products of combustion. The heat from the flame and products of combustion is transmitted through the walls of the boiler sections to heat the water therein to generate steam. Steam from the boiler 6 flows through a steam pipe 15 to chamber 16 of selective valve 9 and a valve element 17 in the chamber directs the steam through the conduit 18 to the refrigeration system 7 or through the conduit 19 to the heating system 8.

The heat operated refrigeration system 7 is shown in Fig. 1 as an absorption system of the type illustrated and described in United States Letters Patent to Albert R. Thomas et al., 2,282,503, issued May 12, 1942, and entitled Refrigeration. Such an absorption refrigeration system operates in a partial vacuum and utilizes a refrigerant such as water and a liquid absorbent such as a solution of lithium bromide. The refrigeration system comprises a generator 20, condenser 21, evaporator 22, absorber 23 and heat exchanger 24 interconnected for the flow of refrigerant and absorbent. Generator has at least one vapor liquid-lift tube 25 connected between a lower inlet chamber 26 and an upper separating chamber 27 and the lift tube is enclosed in a-jacket 28 providing a heating chamber 29 therebetween. The heat of the steam supplied to the heating chamber 29 is transmitted through the Wall of the lift tube 25 to expel refrigerant vapor from absorption solution therein and lift the solution into the separating chamber 27 by vaporlift action.

Vapor from the separating chamber 27 flows through the conduit 30 to the condenser 21. The condenser 21 is illustrated diagrammatically as comprising a chamber 31 having a cooling coil 32 therein. Liquid refrigerant from the chamber 31 of condenser 21 flows by gravity through a pipe 33 into the top of evaporator 22 illustrated in the form of a serpentine coil having spaced heat transfer fins 34. Refrigerant vapor from the evaporator coil 22 flows to the absorber 23. The absorber 23 is in the form of a hermetically sealed shell or casing 35 having heat transfer coils 36 therein and liquid distributing means 37 overlying the coils for distributing absorption liquid for gravity flow over the coils.

Simultaneously with the flow of refrigerant vapor to the condenser 21, absorption solution weak in refrigerant flows by gravity from the separating chamber 27 to the liquid distributor 37 in absorber 23 in a path of flow inciuding conduit 38, outer passage 39 of heat exchanger 24 and conduit 40. Due to the high affinity of the refrigerant, water, for the absorption solution, lithium bromide, the refrigerant evaporates in the evaporator 22 at a low pressure and temperature to produce a refrigerating efiect and the refrigerant vapor is absorbed in the absorption solution as fast as it is formed in the evaporator. The absorption solution strong in refrigerant flows by gravity from the absorber 23 to the inlet chamber 26 of generator 20 in a path of flow including conduit 41,

3 inner passage 42 of liquid heat exchanger 24 and conduit 43.

The heating system comprises a radiator 8 having spaced headers 47 with finned tubes 4% extending between the headers. The steam conduit 19 from the selective valve it is connected to one of the headers 47 and steam flows through the tubes 48 in parallel and condensate returns through the lowermost tube and conduit 19 back to the selective valve 9. Both the heating chamber 29 for the generator 20 of the refrigeration system and a header 47 of the heating system are vented to the atmos phere by a common vent pipe 49 to maintain the steam from the boiler 6 at atmospheric pressure. Condensate drains from chamber 16 of selective valve 9 back to boiler 6 through a conduit 50 and condensate is returned from the heating chamber 29 of generator 26 by apparatus later to be explained in detail.

Cooling tower 19 is usually located at a place remote from the refrigeration unit and may be of any suitable construction. As illustrated, the cooling tower is generally similar to that illustrated and described in a prior United States Letters Patent 2,562,827 issued July 31. 1951. Suffice it to state herein that the cooling tower comprises an upright casing 52 having a fan 53 at the top of the casing, a sump 54 at the base of the casing, packing 55 in the intermediate portion of the casing, distributing nozzles 56 between the fan and the packing and a water makeup valve 57 in the sump. A pump 53 at the base of cooling tower it) draws water from sump 54 through a filter 54a and circulates it in a circuit through the cooling coils 36 of absorber 23 and cooling coil 32 of con-- denser 21. The circuit comprises a conduit connected between the outlet from the pump 58 and a water operated aspirator 6b, later to be described in detail, a conduit 61 connecting the outlet end of the aspirator to one end of the cooling coil 36 in absorber 23, a conduit 62 connecting the outlet from the cooling coil 36 to one end of the cooling coil 32 of condenser 21 and a conduit 63- connecting the opposite end of the condenser cooling coil 32 to the nozzles 56 in the cooling tower.

While the apparatus thus far described is illustrated diagrammatically in Fig. 1, the commercial apparatus has all of the elements of the system mounted on a frame to provide a self contained unit. To conserve space and maintain the overall height of the unit to a minimum the boiler 6 and generator 26 are both located on the base of the frame so that the bottom of the heating cham ber 29 is located below the liquid level L in the boiler 6 as shown in Fig. 1.

In accordance with the present invention apparatus is provided which utilizes the flow of water in the cooling water circuit to produce a force for lifting condensate from the heating chamber of the refrigeration system for gravity return to the boiler. Preferably, the same force is also utilized to inject flue gas into the cooling water to reduce or prevent carbonate scale from forming on the heat transfer surfaces. In the embodiment illustrated. the apparatus comprising the aspirator 60 draws gas from a source at atmospheric pressure, preferably flue gas from the boiler, and utilizes the flow of the flue gas to lift condensate from the heating chamber of the refrigeration system to a level above the boiler.

In Fig. 1 the apparatus is shown as comprising a vessel 65 located above the boiler 6 with a suction conduit 66 connecting the top of the vessel to the aspirator 60 and a drain conduit 67 connecting the bottom of the vessel into the boiler. Between the heating chamber 29 and side of vessel 65 is a gas operated liquid-lift 68 having a sump 69 connected to the bottom of the chamber by a connection 70 and an upright lift tube 71. The lower end of the lift tube 71 projects into the sump 69 to a PO sition adjacent the bottom thereof and the upper end of the lift tube is curved and projects into the side of the vessel 65 adjacent the top thereof. A flue gas conduit '72 connects the hood 12 of boiler 6 to the sump 69 above 4 the liquid level and a by-pass conduit 73 connects the conduit 72 to the side of the vessel 65 adjacent its top.

As illustrated in Fig. 2, the aspirator 60 is in the form of a venturi tube having a converging portion 74 and a diverging portion 75 to provide a throat 76 therebetween. it is well understood that the flow of water through a venturi tube such as illustrated at 60 in Fig. 2 will produce a suction at the throat 76 and a small bore 77 is provided in the side of the tube at the throat which is conncctcd to the suction line 66 by a suitable pipe coupling 7%. A check valve 78 is connected in the suction line 66 which permits the flow of flue gas to the throat 76 of the venturi tube 60 but prevents the flow of water from the venturi tube to the vessel 65. While not necessary to the present invention, the check valve 78 is preferably of a restricting type to limit the flow of flue gas to the venturi tube. As illustrated on Fig. 3 the check valve 78 has a seat 79 and a ball 80 therein for closing the conduit 66 to the how of liquid and a seat 81 having grooves 82 therein for permitting a restricted flow of gas therethrough to the aspirator 60.

A control arrangement is provided for alternately closing and opening the drain conduit 67 and by-pass conunit 73 simultaneously to first lift condensate into the easel 65 and then drain the condensate to the boiler 6. T he control arrangement comprises a valve 85 in the drain conduit 67, a valve 86 in the by-pass conduit 73 and a timing device such as a clock 87 for simultaneously actuating the valves 85 and 86. As illustrated diagramruatically in Fig. 1, the valves 85 and 86 are turned by a shaft 83 operated by the clock 87. A preferred form of the invention having now been described in detail, the mode of operation is explained as follows.

To initiate operation of the apparatus, the fuel burners are ignited to heat the boiler 6 and generate steam i When heating is desired the valve element 17 of ective valve 9 is shifted to close conduit 18 to the geration system 7 and open conduit 19 to the heat ing system 8. Steam then flows from the boiler 6 through the conduit 19 to one of the headers 47 of the radiator 8 and then through the finned tubes 45 between the headers. Air directed over the finned tubes 48 is eat-ed and the condensate from the radiator returns through the conduit 19 to the chamber of the selective valve 9 and from there back to the boiler through the condensate return conduit 50.

When cooling or dehumidification is required, the valve element 17 of the selective valve 9 is actuated to close conduit 19 to the heating system 8 and open the conduit is to the refrigeration system 7. Steam then flows from the boiler 6 through the conduit 18 to the heating chamoer Zi of the generator 20. The heat of the steam is transmitted through the lift tube 25 to expel refrigerant vapor from absorption solution and the expelled vapor lifts the solution to the separating chamber 27. Simultaneously operation of the cooling tower 10 is initiated and pump 55 circulates water through the cooling water circuit. The water flows from the pump 53 through conduit 59, venturi tube aspirator 60, conduit 61, cooling coils 36 in absorber 23, conduit 62, cooling coil 32 of condenser 21 and conduit 63 to the nozzles 56 in the cooling tower. Water is delivered from nozzles 56 in finely divided form onto the packing 55 for gravity flow to sump 54 and is contacted during such flow by air flowing in the opposite direction. Such air and liquid contact causes an evaporation of a portion of the water to reduce its temperature and the cooled water accumulates in the sump 54 where it is again recirculated through the cooling water circuit.

Refrigerant vapor expelled in the generator 20 is delivered through the vapor conduit 39 to the condenser 21 where it is condensed to a liquid and the liquid refrigerant flows from the condenser 21 to the evaporator 22 through pipe 33. Some means such as a restricting orifice, not shown, is provided in the pipe 33 to permit the flow of liquid refrigerant therethrough while maintaining a difference in pressure between the condenser 21 and evaporator 22. Simultaneously, absorption solution weak in refrigerant flows by gravity from the separating chamber 27 to the liquid distributing means 37 in the absorber 23 in a path of flow comprising conduit 38, outer passage 39 of liquid heat exchanger 24 and conduit 40. Due to the high aflinity of refrigerant, water, for the absorption solution, lithium bromide, the refrigerant vapor is absorbed in the absorption solution at a rapid rate which reduces the pressure and temperature at which the refrigerant evaporates in the evaporator 22 to produce a cooling or refrigerating effect. Thus, air flowing over the finned coils of the evaporator 22 is cooled and the air is delivered to an enclosure to be conditioned. Absorption solution strong in refrigerant flows by gravity from the absorber 23 to the inlet chamber 26 of the generator in a path of flow comprising the conduit 41, inner passage 42 of the liquid heat exchanger 24 and conduit 43 to complete the refrigeration cycle. During operation of the refrigeration system the heat of absorption and heat of condensation is transmitted to the water circulating in the cooling water circuit.

Condensate from the steam delivered to the heating chamber 29 accumulates at the bottom and flows through the connection 70 into the sump 69 of the gas operated liquid-lift 68. For purposes of description let it be assumed that at any particular instant the valves 85 and 86 are in a position to close the drain conduit 67 and bypass conduit 73. The flow of cooling Water through the aspirator 60 produces a suction at the throat 76 which draws gas and vapor through the suction line 66 to partially evacuate the vessel 65. The partial vacuum formed in the vessel 65 will cause condensate in the sump 69 to rise in the lift tube 71 and be delivered into the vessel.

This operation will continue until the liquid level in the sump 69 falls below the end of the left tube 71 at which time flue gas from the hood or casing 12 of the boiler 6 will be drawn through the flue gas conduit 72 and sump 69 into the lift tube 71. It will be understood that condensate is being continually formed in the heating chamber 29 and delivered to the sump 69 so that the liquid level therein will continually rise above and fall below the end of the lift tube 71. Thus, alternate slugs of condensate and flue gas will enter the lift tube 71 and be drawn into the vessel 65, the flue gas continuing through the suction conduit 66 and entering the cooling water at the throat 76 of the venturi tube 68. When a restricting type of check valve 78 is used as illustrated in Fig. 3, the amount of flue gas entering the cooling water is controlled by the size of the grooves 82 in the seat 81 of the check valve. The condensate, however, accumulates and is stored in the vessel 65.

After a predetermined time period the clock 87 operating through the shaft 88 turns the valves 85 and 86 to open the drain conduit 67 and bypass conduit 73. As the by-pass conduit 73 is connected to the hood 12 of the boiler 6 at atmospheric pressure, the vessel 65 is subjected to a pressure approaching atmospheric. The opening of valve 85 then permits accumulated condensate in the vessel 65 to flow by gravity from the vessel through the drain conduit 67 to the boiler 6. However, flue gas continues to be delivered from the boiler 6 to the cooling water in the path of flow through the bypass conduit 73, vessel 65, check valve 78 and conduit 66. After a further predetermined period of time the valves 85 and 86 are actuated by the clock 87 to close the drain conduit 67 and by-pass conduit 73 and the apparatus then operates as previously explained to lift condensate from the heating chamber 29 to the vessel 65 through the gas operated liquid-lift 68 and deliver flue gas to the cooling water. The clock 87 and valves 85 and 86 are so geared as to close conduits 67 and 73 to lift condensate for predetermined periods of time, for example, five minutes, and open the conduits to drain condensate for a predetermined period of time, for ex ample, one minute, in alternate sequence. Between periods of operation of the refrigeration system the check valve 78 prevents water from the cooling circuit from flowing into the boiler 6.

While the valves and 86 are illustrated diagrammatically in Fig. l as being operated by a clock 87, a preferred arrangement comprises an electric control having a clock operated switch as illustrated in Fig. 4. In the arrangement illustrated in Fig. 4, the valves 85 and 86 are each shown as comprising a valve housing 90 having a valve seat 91 and valve element 92. The valve stem 93 has an armature 94 located axially in a solenoid coil 95 for lifting the valve 92 away from the seat 91 when energized and a spring 96 for closing the valve. The solenoid coil 95 for each of the valves 85 and 86 are connected in parallel in an electric circuit having a source of electric current such as a battery 97 and a drum type switch 98. The drum type switch 98 has alternate conducting portions 99 and insulating portions 100 and the drum is continuously rotated by a prime mover 101. While the prime mover is illustrated in the form of a clock as a timing device, it preferably is in the form of a synchronous electric motor having electrical connections 102 and geared so as to rotate the drum 98 at the desired rate. Brushes 103 and 104 bear on the drum 98 to alternately connect and disconnect one side of the battery 97 to one end of the solenoid coil 95 of the respective valves 85 and 86 through the conductors 105 and 106. The opposite ends of the solenoid coils 95 are connected together and to the opposite side of the battery 97 through a conductor 107. The electric control arrangement illustrated in Fig. 4 operates the valves 85 and 86 in the same way as explained with respect to Fig. 1 to alternately close the drain and by-pass conduits 67 and 73 to lift condensate and deliver flue gas to the cooling water and open the conduits to drain condensate and continue to deliver flue gas to the cooling water.

It will now be observed that the present invention provides an apparatus utilizing the flow of cooling water to provide a force for lifting condensate from the heating chamber for gravity return to the boiler. It will still further be observed that the present invention provides an apparatus for simultaneously drawing flue gas into the cooling water and returning condensate from the heating chamber to the boiler. It will still further be observed that the present invention provides an apparatus for alternately producing a suction to lift condensate to a level above the boiler and releasing the suction to permit the raised condensate to return by gravity to the boiler.

While a single embodiment of the invention is herein illustrated and described, it will be understood that modiflcations may be made in the construction and arrangement of elements without departing from the spirit and scope of the invention. Therefore, without limitation in this respect, the invention is defined by the following claims.

I claim:

1. In combination with a heat operated refrigeration system having a heating chamber and a heat rejecting element, conduit means for flowing cooling water in heat exchange with the heat rejecting element, a boiler for producing vapor for the heating chamber and flue gas for treating the cooling water, and apparatus connected to the boiler, heating chamber and conduit means and operated by the flow of cooling water in the latter to produce a force for simultaneously injecting flue gas into the water and returning condensate from the heating chamber to the boiler.

2. In combination with a heat operated refrigeration system having a heating chamber and a heat rejecting element, conduit means for flowing cooling water in heat exchange with the heat rejecting element, a boiler for producing vapor for the heating chamber and flue gas for treating the cooling water, an aspirator in the conduit means and utilizing the flow of water to produce a suction, and apparatus connected to the aspirator, boiler and heating chamber and utilizing the suction produced by the aspirator to deliver line gas through the aspirator into the Water and lift condensate from the heating chamber to a level above the boiler.

3. In combination with a heat operated refrigeration system having a heating chamber and heat rejecting element, conduit means for flowi v cooling water in heat exchange with the heat rcjec g element, a boiler for producing vapor or the heating chamber and flue gas for treating the cooling water. an as irator in the conduit means and utilizing the dew of cool 5 water therethrough to produce a suction, conduit means connecting the boiler and aspirator to draw iiue nto the water, and conduit means connecting the chamber and boiler and having a portion common with the conduit means connecting the boiler and aspirator, said last named conduit utilizing the flow of line gas to lift condensate from the chamber for gravity flow to the boiler.

4. In combination with a heat operated refrigeration system having a heating chamber and a heat rejecting element, a circuit including a cooling tower for circulating cooling water in heat exchange with the heat rejecting element, a boiler for producing vapor for the heating chamber and flue gas for treating the cooling Water, a venturi tube in the cooling Water circuit, a conduit connecting the boiler and venturi tube, said venturi tube utilizing the flow of water thercthrough to draw flue gas through the conduit into the Water, and a liquid-lift tube in the line gas conduit and connected to the heating chamber and boiler, said lift tube utilizing the suction of the venturi tube and flow of flue gas therethrough to raise condensate from the healing chamber for return to the boiler.

5. in combination with a heat operated refrigeration system having a heat receiving element a heat rcjecting element, a chamber for heating the heat-receiving element, a boiler connected to deliver or the heating chamber and having a liquid level re the bottom of the chamber, a fuel burner for heating the boiler, a cooling tower, a circuit for circulating cooling Water through the cooling tower and. in heat exchange relation with the heat rejecting element. a condensate return conduit connecting the heating chamber boiler, and apparatus connected to the boiler, heating chamber and cooling water ircuit and utilizing the flow of water in the latter to produce a force for drawing a portion of the products of combustion from the burner through the condensate return conduit into the cooling water and lift condensate from the heating chamber for return to the boiler.

6. In combination with a neat operated refrigeration SYSLGHI having a heating hamber, a boiler for producing vapor and flue gas, a conduit for delivering vapor from the boiler to the heating chamber, said boiler a liquid level above the bottom othe heating chamber, a gas operated liquiddift connecting the heating chamber and boiler, and apparatus for causing flue gas from the boiler to flow through the licnilditt to raise condensate from the heating chamber a le el above the boiler.

7. In combination with a heat operated refrigeration system having a heating chamber, a boiler connected to deliver vapor to the chamber and having liquid level above the bottom of the chamber, heating means for the boiler raving a fuel burner flue for the products of combustion. and condensate r urn means connecting the bottom of the heating chamber and top of the boiler comprising a gas o erated liq iidlift tube and means for causing a porti. a of the flue gas from the burner to llovv through the lift tube.

8. in com ination with a heat operated refrigeration system having a heat receiving element with a heating chamber and a heat rejecting element, conduit means for flowing cooling water exchange with the heat re- .jecting element, a bOlifii connected to deliver vapor to the heating chamber, said boiler having a liquid level iii) above the bottom of the heating chamber, and a condensate return apparatus connected to the heating chamber, boiler and conduit means and operated by the flow of cooling water in the latter to produce a force for lifting condensate from the heating chamber for return to the boiler.

9. in combination with a heat operated refrigeration unit having a heat receiving element with a heating chamber and a heat rejecting element, a boiler connected to deliver vapor to the heating chamber and having a liquid level above the bottom of the chamber, conduit means for flowing cooling Water in heat exchange with the heat rejecting element, condensate return means connected to toe heating chamber and boiler and comprising a liquidlift extending upwardly above the boiler, and an aspirator in the conduit means and connected to the condensate return means, said aspirator utilizing the flow of cooling Water in the conduit means to lift condensate in the liquid-lift for return to the boiler.

10. In combination with a heat operated refrigeration system having a heat receiving element with a heating chamber and a heat rejecting element with a heat exchanger, a boiler connected to deliver steam to the heating chamber and having a liquid level above the bottom of the chamber, conduit means for flowing cooling water through the heat exchanger, a water operated aspirator in the conduit means, and condensate return means having a conduit connecting the bottom of the heating chamber and aspirator, a storage vessel in said conduit above the boiler, a drain conduit connecting the bottom of the vessel to the boiler, a vent conduit connecting the top of the vessel to the atmosphere, and an intermittently operated valve in the last named conduit for alternately closing and opening the latter for lifting condensate from the heating chamber to the vessel and delivering conensate from the vessel to the boiler.

ll. In combination with a heat operated refrigeration system having a heat receiving element with a heating chamber and a heat rejecting element with a heat e5.- changer, a boiler connected to deliver steam to the heating chamber and having a liquid level above the bottom of the chamber, conduit means for flowing cooling water through the heat exchanger, a water operated aspirator in the conduit means, and condensate return means having a conduit connecting the bottom of the heating chamber and aspirator, a vessel in said last named conduit above the boiler, a drain conduit connecting the bottom of the vessel to the boiler, a vent conduit connecting the top of the vessel to the atmosphere, a valve in each of the drain and vent conduits, and timing means for alternately opening and closing the valves simultaneously to lift condensate from the heating chamber to the vessel and deliver condensate from the vessel to the boiler.

12. in combination With a heat operated refrigeration system having a heat receiving element with a heating chamber and a heat rejecting element with a heat exchanger, a boiler for producing steam for the heating chamber and flue gas for treating the cooling water, said boiler having a liquid level above the bottom of the chamber, conduit means for flowing cooling water through the heat exchanger, a venturi tube in the conduit means, a conduit connecting the bottom of the heating chamber and venturi tube and having a vessel therein above the boiler, a line gas conduit connecting the boiler and last name-d conduit to deliver flue gas thereto, a bypass conduit connecting the due gas conduit to the top of the vessel, a drain conduit connecting the bottom of the vessel to the boiler, a valve in each of the by-pass and drain conduits, respectively, and timing means for opening and closing the valves to alternately lift condensate from the chamber to the vessel and deliver condensate from the vessel to the boiler while continuously supplying flue gas to the cooling water.

13. In combination with a heat operated refrigeration system having a heat receiving element with a heating chamber and a heat rejecting element with a heat ex- 9 10 changer, a cooling tower, conduit means for circulating References Cited in the file of this patent water from the cooling tower through the heat exchanger and then back to the cooling tower, a boiler for producing UNITED STATES PATENTS vapor for the heating chamber and flue gas for treating the cooling water, a venturi tube in the cooling water circuit, 5 838,641 Paul Dec. 18, 1906 a conduit connecting the boiler and venturi tube to draw 1,263,845 Brornan Apr. 23, 1918 flue gas into the water, a condensate return conduit con- 1,771,077 Dunham July 22, 1930 necting the heating chamber and boiler, said flue gas con- 1,960,914 McCoy May 29, 1934 duit and said condensate return conduit having a portion 2,349,396 Andersson May 23, 1944 in common so that the flow of flue gas lifts condensate 10 2,374,521 Anderson Apr. 24, 1945 from the heating chamber for return to the boiler. 2,515,319 Sherwood July 18, 1950 

1. IN COMBINATION WITH A HEAT OPERATED REFRIGERATION SYSTEM HAVING A HEATING CHAMBER AND A HEAT REJECTING ELEMENT, CONDUIT MEANS FOR FLOWING COOLING WATER IN HEAT EXCHANGE WITH THE HEAT REJECTING ELEMENT, A BOILER FOR PRODUCING VAPOR FOR THE HEATING CHAMBER AND FLUE GAS FOR TREATING THE COOLING WATER, AND APPARATUS CONNECTED TO 